Abdominal manifestations of extraosseous myeloma: cross-sectional imaging spectrum

Extraosseous myeloma, defined as the myelomatous involvement outside the skeleton system, is rare and often associated with advanced multiple myeloma. There has been a recent increase in the clinicoradiological incidence of this entity, possibly secondary to increased survival of patients and frequent use of imaging. This has led to the development of new clinical staging guidelines for multiple myeloma, which include the use of imaging modalities positron emission tomography/computed tomography and magnetic resonance imaging for accurate detection and optimal management. The aims of this review were to discuss the significance of identification of extraosseous disease, to describe the spectrum and common sites of extraosseous involvement in the abdomen, and to review the imaging findings of extraosseous myeloma in the abdomen.